The Scaled Composites Stratolaunch, a huge twin-fuselage aircraft intended for ferrying rockets into the stratosphere, has taken its first flight, officially becoming the largest plane ever built, in terms of wingspan.
The 117-meter wide plane took off from a runway in California's Mohave Desert and flew for 2.5 hours at altitudes of up to 5,000 meters at speeds of up to 304 km/h.
Powered by six Boeing 747 engines, the plane is intended to climb twice as high, and with a space rocket strapped underneath.
As taking off from the ground is the most fuel-consuming portion of a rocket launch, the idea of a stratosphere launch is intended to allow for the increase of a rocket's payload, also allowing for a faster turnaround between launches, say specialists at both Stratolaunch and Virgin Orbit, according to a CNBC report.
The widest plane ever built prior to the Stratolaunch was the mid-20th-century H-4 Hercules — aka ‘Spruce Goose' — built by famous US aviator Howard Hughes. The Spruce Goose took its only flight on 2 November 1947. After Hughes's death, the airplane was installed at the Evergreen Aviation & Space Museum in California.
Stratolaunch was initiated by late Microsoft co-founder Paul Allen in 2011. Allen died of lymphoma in October 2018, only a handful of months before his creation could take flight for the first time.
"We all know Paul would have been proud to witness today's historic achievement," said Jody Allen, chairman of Vulcan, which runs Allen's estate. "The aircraft is a remarkable engineering achievement and we congratulate everyone involved."
Stratolaunch initially signed a partnership contract with SpaceX, but later switched to Northrop Grumman-owned Orbital ATK to take its Pegasus XL rocket to the stratosphere for launch. The company initially planned to develop its own fleet of rockets but scrapped the plan in January, CNBC report says.